Events at Physics |
Events During the Week of December 6th through December 13th, 2020
Sunday, December 6th, 2020
- Academic Calendar
- All classes move to virtual format for the remainder of the semester
- Abstract: *Note: actual end time may vary.*
Monday, December 7th, 2020
- Academic Calendar
- All classes move to virtual format for the remainder of the semester
- Abstract: *Note: actual end time may vary.*
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Demonstration of helium exhaust enhancement during resonant magnetic perturbation (RMP) field application at DIII-D
- Time: 12:00 pm
- Place: Zoom Meeting
- Speaker: Edward Hinson, UW Engineering Physics department
- Abstract: It is shown for the first time in a diverted tokamak that
key metrics for continuous fusion, effective helium particle
confinement time, 𝛕_p*He, and its ratio with energy confinement,
𝛕_p*He/𝛕_E, were reduced by a factor of 2-3 during suppression of
edge localized modes (ELMs) by resonant magnetic field perturbations
(RMPs) over the unperturbed ELMy case. Reduced 𝛕_p*He during RMP was
observed in the core, edge, and pump plenum, where higher helium
pressure and concentration were also found. Elevated ionized helium
line emission during ELM suppression, with a decay time matching
𝛕_p*He, was measured at the inner strike point, suggesting more
helium in the unconfined region. These observations suggest that
processes during application of RMPs better retain helium at the edge,
in excess of that expected from deuterium ‘pumpout,’ where it is
pumped more quickly. A multi-reservoir model, derived from a finite
volume approximation of the continuity equation with diffusive and
convective transport, fits the helium time evolution at each of the
above-mentioned measurements well. Transport parameters obtained from
these fits indicate the data are consistent with strongly increased
transport of helium in the separatrix region during RMP application,
although higher core transport is also found. These findings, which
were obtained in ITER-shaped plasmas, provide evidence that
application of RMP ELM suppression in future devices such as ITER may
be capable of matching or exceeding the helium impurity exhaust
produced by the ELM events themselves, thereby helping to avoid helium
ash buildup in a burning regime, and maintain high fusion gain.
Connection information:
Join Zoom Meeting
Meeting ID: 991 5610 7574
Passcode: 883688 - Host: Paul Terry
Tuesday, December 8th, 2020
- Academic Calendar
- All classes move to virtual format for the remainder of the semester
- Abstract: *Note: actual end time may vary.*
- PGSC Professional Development Seminar
- Okay, Google: Help Me with My Resume
- Time: 2:30 pm - 3:30 pm
- Place:
- Speaker: Homer Wolfmeister, Google
- Abstract: Crafting an attractive resume is a skill that takes practice to develop, but the process becomes much easier once you know what search committees are looking for. Sharing his experience screening Google applicants, Homer Wolfmeister will overview the components of a strong resume for typical industry careers. He will also outline the hiring process from initial screenings, to resume evaluation, to getting an interview. There will be time at the end for questions about any part of the hiring process.
- Network in Neutrinos, Nuclear Astrophysics, and Symmetries (N3AS) Seminar
- Potential Effects of Fast Neutrino Flavor Transformations on Neutrino-Driven Wind and Supernova Nucleosynthesis
- Time: 3:30 pm
- Place:
- Speaker: Andre Sierverding , University of Minnesota
- Abstract: Recently, the possibility that fast neutrino flavor transformations may occur very close to the core of a collapsing massive star has received a lot of
attention. Such transformations would affect the conditions of the wind driven by the intense neutrino emission from a proto-neutron star (PNS) where nuclei
heavier than Fe can be produced. We show that flavor transformations would lead to more proton-rich outflows and more favorable conditions for a nu-p process
to occur. Similarly, the conditions of the innermost, neutrino-heated supernova ejecta would also be affected and I illustrate possible effects with nucleosynthesis
calculations based on a 3D supernova model.
- Host: Baha Balantekin
- Council Meeting
- Time: 4:00 pm - 5:00 pm
- Place: Virtual
- Speaker: Sridhara Dasu, UW-Madison
- Host: Sridhara Dasu, Department Chair
- WARF Innovation Awards
- Time: 4:00 pm - 5:00 pm
- Place: sign up to receive the webinar link:
- Speaker: Cary Forest, UW–Madison Physics
- Abstract: Each fall the WARF Innovation Awards recognize some of the best of inventions at UW-Madison. WARF receives hundreds of new invention disclosures each year. Of these disclosures, six were selected as finalists for the WARF Innovation Awards. This year's finalists include:
High-Energy Plasma Generator for Medical Isotope Production, Nuclear Waste Disposal & Power Generation
Cary Forest (Physics)
Jay Anderson (Physics)
John Wallace (Physics)
Robert Harvey (CompX)
Yuri Petrov (CompX)
See more about the awards and watch videos of the six finalists' projects at: Wednesday, December 9th, 2020
- Academic Calendar
- All classes move to virtual format for the remainder of the semester
- Abstract: *Note: actual end time may vary.*
- Department Meeting
- Time: 12:15 pm - 1:30 pm
- Place: Virtual see "abstract" for connection info
- Speaker: Sridhara Dasu, Department Chair, UW-Madison
- Meeting Coordinates: Meeting number: 120 392 9242 Password: Q5EjaTz3Pk3 (75352893 from phones) Join by video system Dial 1203929242@uwmadison.webex.com You can also dial 173.243.2.68 and enter your meeting number. Join by phone +1-415-655-0001 US Toll +1-312-535-8110 United States Toll (Chicago) Access code: 120 392 9242
- Host: Sridhara Dasu, Department Chair
Thursday, December 10th, 2020
- Academic Calendar
- Last day of instruction
- Abstract: *Note: actual end time may vary.*
- Academic Calendar
- All classes move to virtual format for the remainder of the semester
- Abstract: *Note: actual end time may vary.*
- Cosmology Journal Club
- Time: 12:00 pm - 1:00 pm
- Abstract: Cosmology Journal Club is back! We will be having virtual meetings this semester.
Each week, we start with a couple scheduled 15 minute talks about one's research, or an arXiv paper. The last 30 minutes will typically be open to the group for anyone to discuss an arXiv paper.
All are welcome and all fields of cosmology are appropriate.
Contact Ross Cawthon, cawthon@wisc, for more information. - NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Muon Collider Explorations
- Time: 1:00 pm - 4:00 pm
- Place:
- Speaker: Sarah Demers, Vladimir Shiltsev, Tao Han, Simone Pagan Griso, US HEP Community
- Abstract: Workshop
- Host: Sridhara Dasu
- Astronomy Colloquium
- Multi-messenger Astrophysics: Probing Compact Objects with Cosmic Particles
- Time: 3:30 pm - 5:00 pm
- Place: Zoom meeting(see Abstract ) Coffee and tea 3:30pm, Talk 3:45 PM
- Speaker: Ke Fang, UW Astronomy Department
- Abstract: The study of compact objects such as black holes and neutron stars is an important component of modern astrophysics. Recent detections of astrophysical neutrinos, gamma-rays, ultrahigh energy cosmic rays, and gravitational waves open up opportunities to study compact objects with multi-messengers. In this talk, we first review the latest progress in Astroparticle Physics, including some surprising puzzles revealed by new observations. We demonstrate that the key to Multi-messenger Astrophysics is to understand and establish the link between the messengers. We then illustrate how to reach this goal from both theoretical and observational perspectives. From the theoretical side, we show that high-energy particle propagation in the vicinity of compact objects may play an important role in connecting multi-wavelength observation and source physics. From the observational side, we investigate analysis frameworks aiming to exploit data across multiple wavelengths and messengers.
Zoom URL:
Meeting ID: 885 1389 6776
Passcode: 713070
- Host: Professor Ellen Zweibel
Friday, December 11th, 2020
- Academic Calendar
- Study day
- Abstract: *Note: actual end time may vary.*
- Theory Seminar (High Energy/Cosmology)
- Electric-Magnetic S-matrix
- Time: 2:00 pm - 3:00 pm
- Place: For zoom link, sign up at:
- Speaker: Sungwoo Hong, Cornell University
- Abstract: In the first part of the talk, I will argue that an asymptotic multi-particle state built as a product of one-particle states is not fully general. In addition, I will show that the more general asymptotic multi-particle state carries extra quantum number, pairwise-helicity, on top of the regular labels such as momentum and spin/helicity of each particle. In the second part of the talk, the S-matrix for the scattering of electrically and magnetically charged particles will be considered. After discussing several non-conventional properties of the electric-magnetic S-matrix, including the extra pairwise-helicity carried by the electric-magnetic asymptotic state and the associated crossing symmetry violation, modern on-shell scattering amplitude method will be motivated as a way to construct the electric-magnetic S-matrix. Pairwise spinor-helicity variables as additional building blocks for the electric-magnetic S-matrix will then be introduced. Discussion on the general three-point amplitudes and resulting generalized spin-helicity selection rules comes next. Finally, I describe the partial-wave decomposition of the 2 to 2 electric-magnetic S-matrix, showing that the well-known results based on QM computations are reproduced with a small input about the phase shift. In particular, the helicity-flip in the lowest partial wave is shown to be a simple consequence of a generalized spin-helicity selection rule. Furthermore, the full angular dependence for the higher partial waves is shown to agree with QM results. Our work represents a remarkable success of on-shell methods for non-perturbative physics, especially when the Lagrangian description fails.
- Host: Lars Aalsma
- Department Coffee Hour
- Time: 3:30 pm - 4:30 pm
- Place:
- Abstract: Join us weekly for an informal virtual coffee hour! Catch up with others in the department, tell us how things are going, and impress everyone with your Zoom background skills. Coffee Hour is open to any and all faculty, staff, and students in the department. Sometimes we have a topic, and we'll try to get that topic posted here in advance or sent out by email before each coffee hour.
- Host: Department
Saturday, December 12th, 2020
- Academic Calendar
- Summary period (exams)
- Abstract: *Note: actual end time may vary.*
Sunday, December 13th, 2020
- Academic Calendar
- Summary period (exams)
- Abstract: *Note: actual end time may vary.*
- Academic Calendar
- Commencement
- Abstract: *Note: actual end time may vary.*